The present invention relates to a light unit for a vehicle arranged to control illumination which is performed by the light unit in any one of driving modes classified in accordance with the diving environment in which the vehicle is driven.
A conventional apparatus for controlling the illumination performed by a light unit based on the driving environment includes an image pickup means for always monitoring a state of a road or the like in front of the vehicle to successively change the distribution of light which is emitted from the light unit in a manner adaptable to change in information indicating result of monitoring.
The environment in which a vehicle is driven includes a variety of roads, such as mountain roads, roads in urban areas, expressways, bypass roads, and the like. Moreover, the traffic density varies according to time and places. Since the driving environment for a vehicle varies according to the present position of the vehicle and a lapse of time, the above-mentioned successive control of the illumination which is performed by the light unit excessively increases the load which must be borne by a drive portion of the light unit, thereby causing the durability of the drive portion to deteriorate. Further, if the illumination control over sensitively responds to change in the driving environment, the vehicle""s driveability deteriorates.
To prevent the above-mentioned problems, it might be feasible to employ a method of reducing the response speed of the illumination control performed by the light unit. However, a slowed controlling operation is unsafe if the driving environment is changed rapidly.
An object of the present invention is to control the illumination performed by a light unit in a manner adaptable to change in the driving environment in which a vehicle is driven without any disadvantage load increases being borne by a drive portion of the light unit and any delay of control.
To achieve the above-mentioned problems, according to one aspect of the present invention, a light unit for a vehicle comprises driving-environment detecting means for detecting information indicating a driving environment provided by a path on which a vehicle is driven; mode determining means for determining a driving mode which is included among driving modes that represent combinations of information detectable by the driving-environment detecting means and which is dynamically changed when the driving environment is changed during driving of the vehicle; and illumination control means for controlling illumination which is performed by the light unit of the vehicle in accordance with an instruction signal supplied from the mode determining means and corresponding to the driving mode.
According to the present invention, the mode determining means determines the driving mode of the vehicle in accordance with the detected driving environment in which the vehicle is driven. The illumination performed by the light unit is controlled according to the determined driving mode which changes with the detected driving environment. Thus, excessive response of the control response time or delay in the control with respect to change in the driving environment is prevented.